staging: iio: tsl2x7x: move calibscale_available attribute to IIO_INTENSITY channel

The calibscale_available attribute is currently associated with the
IIO_LIGHT channel but should be associated with the IIO_INTENSITY
channel. This patch corrects that association and it also corrects
lines that were unnecessarily split for the
in_intensity0_integration_time sysfs attribute.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>